Ingredients:
- 5 lbs Ground Beef (80/20 fat ratio)
- 1 tsp Kosher Salt (to taste)
- 1/2 tsp Freshly Ground Black Pepper (to taste)
- 4 slices American Cheese or Sharp Cheddar
- 4 Potato Buns or Brioche Buns
- 2 Tbsp Unsalted Butter
- 1/2 cup Mayonnaise (for sauce)
- 2 Tbsp Ketchup (for sauce)
- 1 Tbsp Yellow Mustard (for sauce)
- 1 Tbsp Sweet Pickle Relish (for sauce)
- 1/2 medium White Onion, thinly sliced
Instructions:
- Mix all 'Secret Sauce' ingredients (mayo, ketchup, mustard, relish) in a small bowl; set aside. Slice onions thinly; set aside. Divide ground beef into 8 equal portions (about 3 oz each) and gently roll into loose balls—do not pack them tight.
- Place a heavy-bottomed cast iron skillet or griddle over high heat and allow it to preheat for 5–7 minutes until screaming hot.
- Place two beef balls onto the hot, dry pan, leaving space between them. Immediately place a square of parchment paper over the top of each ball. Using a sturdy spatula, firmly press down through the parchment paper until the patty is about 1/4 inch thick, ensuring a hard, swift press for maximum surface contact.
- Season the top surface generously with salt and pepper. Cook undisturbed for 1.5–2 minutes until a deep brown, crispy crust forms on the bottom.
- Use the metal spatula to firmly scrape under the patty to lift the crust intact, then flip the patties. Immediately top each patty with a few rings of onion and one slice of cheese. Add a tablespoon of water to an empty space in the pan and quickly cover with a lid for 30 seconds to melt the cheese rapidly.
- While the cheese melts, butter the cut sides of the potato buns and toast them lightly on a separate clean area of the pan until golden brown.
- Remove the lid. Gently stack the two cheesy patties together for each burger (double stack). Spread the bottom bun liberally with the secret sauce, place the double-stacked patty on top, and crown with the lid bun. Serve immediately, repeating the process for the remaining patties.